21356465311 has 4 divisors (see below), whose sum is σ = 21358715112. Its totient is φ = 21354215512.

The previous prime is 21356465309. The next prime is 21356465327. The reversal of 21356465311 is 11356465312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21356465311 - 2¹ = 21356465309 is a prime.

It is a super-2 number, since 2×21356465311² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21356465371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1110601 + ... + 1129666.

It is an arithmetic number, because the mean of its divisors is an integer number (5339678778).

Almost surely, 2^21356465311 is an apocalyptic number.

21356465311 is a deficient number, since it is larger than the sum of its proper divisors (2249801).

21356465311 is an equidigital number, since it uses as much as digits as its factorization.

21356465311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2249800.

The product of its digits is 64800, while the sum is 37.

Subtracting from 21356465311 its reverse (11356465312), we obtain a palindrome (9999999999).

The spelling of 21356465311 in words is "twenty-one billion, three hundred fifty-six million, four hundred sixty-five thousand, three hundred eleven".